We present a new simulation technique for Distributed Feedback lasers in 2D. The method is based on recently
developed Trigonometric Finite Wave Elements (TFWEs) that approximate oscillating and internally reflected
optical waves. Since our method is derived from the Transfer Matrix Method (TMM), the TFWE method
provides exactly the same results as the TMM for 1D problems but it can be extended to higher dimensions and
to time-dynamic simulations. Therefore, large laser structures and the influence of the injected current can be
simulated time-dynamically. Furthermore, the wavelengths of the competing modes can be detected using the
Fast Fourier Transformation.